METHODS FOR PREPARING ALKALI CELLULOSE AND WATER-SOLUBLE CELLULOSE ETHER

摘要

A method for manufacturing a transparent cellulose ether having little water-insoluble part is provided. A method for manufacturing alkali cellulose comprises: a contact process of contacting pulp sheet of sheet state or chip state with alkali metal hydroxide solution at 5-70°C to obtain alkali cellulose reaction mixture; and a dehydration process of dehydrating the reaction mixture.. The amount of the alkali metal hydroxide solution is determined in order for the alkali cellulose to have solid component ratio of 0.3-1.5 alkali metal hydroxide component/pulp. The pulp sheet contains under 0.10 weight% of dichloromethane extract. A water soluble cellulose ether is produced by reacting etherifying agent with the produced alkali cellulose.